Epizootic disseminated toxoplasmosis in captive slender-tailed meerkats (Suricata suricatta).

Fatal disseminated toxoplasmosis was diagnosed in seven captive slender-tailed meerkats (Suricata suricatta) according to clinicopathologic findings and immunohistochemistry. Five of nine meerkats died during an outbreak in late 1994. These included four kits (2.5 to 4.5 months old) and a 4-year-old meerkat. Two other meerkats, both adults, died in 1992 and 1995. Respiratory insufficiency (4/7) and incoordination (3/7) were the most consistent clinical signs. although two of seven meerkats died unexpectedly. At necropsy, the lungs were reddened and noncollapsed (6/7), and had multiple pale round foci (4/7). Yellow foci of necrosis in mesenteric lymph nodes (4/7), splenomegaly (3/7), and hydropericardium (3/7) were other common gross findings. Microscopically, interstitial pneumonia was present in all seven meerkats, being acute to subacute in six of them. Type 2 pneumocyte hyperplasia, aggregates of foamy macrophages, and giant cells were consistently seen. Multifocal to locally extensive necrosis of mesenteric lymph nodes (4/7), mild to severe multifocal necrotizing hepatitis (5/6), and mild nonsuppurative encephalitis (4/6) were also seen. Toxoplasma-like organisms were consistently associated with these lesions and were stained by the avidin biotin peroxidase procedure with an antiserum that does not cross-react with Neospora caninum. Meerkats were most likely infected after an oral, primary exposure to Toxoplasma. Several observations indicate that meerkats may be highly susceptible to toxoplasmosis.